The noise caused by the movement of glass bottles or metal boxes carried by conveyors from a filling station to a finishing, closing, sealing, corking or other station may reach sound levels that are high, or even dangerous or unbearable.
Covering assemblies are already known in the form of a tunnel or box intended to cover the conveyor in order to suppress or at least reduce the noise pollution and provide protection in the form of physical separation from the outside.
These covering assemblies are made from a lateral surface consisting of a series of noise-reducing panels connected together and mounted on a framework fixed to the uprights and to underframes supporting the conveyor. A transparent top enclosure in the form of a tunnel or box with an access hatch enables the conveying to be monitored and safety or maintenance operations to be carried out.
A bottom enclosure provides continuity of the sound insulation and physical protection.
All the parts constituting this protection are fixed to support members secured to the framework, which is itself mounted on the body of the conveyor or the underframes supporting it.
The fixing is effected in a conventional manner using screws, bolts, rivets etc. It does not therefore enable either rapid installation or removal to be carried out.
There are of course access flaps or hatches but these are localised at a few precise points situated almost exclusively on the top surface. These openings allow only limited access to a small area around the entry thus formed. In addition, they represent a significant additional cost.
In this regard, French patent No 2 454 986 in the name of MASSICOT can first of all be cited. This describes an embodiment, the top protection of which, consisting of tunnel-shaped hoods sliding in each other, is combined with a trough-shaped bottom protection provided with a noise-reducing cladding held at the edges by clamps and opening in the manner of a shell.
It should be noted, firstly, that this protection is suitable only for those portions of conveyors which are in a straight line.
Then, the basic components, including the bottom cover and the guide rails, prove to be difficult to remove. Because of this, an operation requiring the removal of these components will inevitably turn out to be slow and difficult.
Next, U.S. Pat. No. 4,093,066 in the name of the COCA COLA Company can be cited, which relates to a noise-reducing module in the general form of a tunnel with an enclosing return on the bottom part of the conveyor.
The lateral faces are sloping. One is opaque, extending beyond the top zone, and the other is produced in the form of a hatch.
These modules can be assembled in linear sequences by means of connecting ribs mounted on supports fixed to the underframes supporting the conveyor.
Special fastenings and a set of tools are required to assemble these modules.
Furthermore, the space to be insulated is not completely closed off. In the lower part there is an unprotected zone.
Finally, it is not possible to protect an entire conveyor system by means of a succession of such modules, since they are suitable only for straight lines.
The fitting of the supporting metal structure and then the installation of each component of the wall, with drilling and mounting of the fixing lugs, adjustment, tightening of screws, all involve significant down-time in terms of man hours.
Furthermore, the wall is difficult to modify. There is no simple way of replacing a single part following damage. Mounting and removal continue to be protracted operations which are difficult to carry out. They very often require the conveyor to be stopped.
As far as the top enclosing wall is concerned, it would be advantageous to be able to open up or free an area for observation and access for the purpose of a maintenance or repair operation on the transfer belt.
This function is at present provided by enclosing flaps mounted on hinges. These panels are difficult to manipulate because they are components of considerable size. In addition, they cannot be detached and are therefore a considerable hindrance for certain types of operation. In addition, replacing them proves to be a long and complicated process.
European patent No 102 910 in the name of the applicant describes an embodiment corresponding to this state of the art.
Furthermore, when bottles are being carried on a transfer unit, whether of the belt conveyor or other type, it happens that the shaking resulting from the motion or from mishandling cause the containers to tilt in such a way that part of their contents is spilt or causes a loss of balance in one or more of them which then fall on one side, spilling their contents and possibly being broken.
With a conveyor which is not protected at its lower part, the glass debris and liquid are scattered over a considerable area of the floor beneath the conveyor belt, access to which is difficult and which is therefore difficult to clean.
A fairing, particularly on the lower part, fulfills the function of guarding the conveyor and retaining and recovering debris and waste or spilled liquids, etc.
Different types of bottom fairing for protecting conveyors are known.
Fixed fairings are not very practical since they are themselves difficult to clean.
The bottom fairing described in French patent No 2 454 986 (MASSICOT) consists of panels mounted so as to pivot by lateral hinges on one side of the conveyor. Each panel is itself hinged to form two lateral parts.
Though this protection affords easy access to the conveyor and enables it to be cleaned, the hinged panels are cumbersome and heavy to manipulate. They form a permanent structure which is made to measure and is difficult to adapt to subsequent modifications of the conveyor.
In addition, if the debris and liquid are retained initially by the hinged panels of the fairing, there is a risk that, when the panel is opened at the bottom, they will be spilt on the floor.
Complete enclosure relates to both lateral enclosure and top and bottom enclosure along the conveyor in its straight, curved and angular parts.